diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2009-07-19 08:44:27 -0500 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2011-12-28 16:25:47 -0600 |
| commit | 8982dea3a77775d7a2a79662f7f18bbf9fe8002a (patch) | |
| tree | 3537eb3db61007149f2ed0e992f113b76d1b0b77 /fs | |
| parent | d59bee2373cb7085e88495ad1747176f1e5b3106 (diff) | |
fs: namespace preemption fix
On RT we cannot loop with preemption disabled here as
mnt_make_readonly() might have been preempted. We can safely enable
preemption while waiting for MNT_WRITE_HOLD to be cleared. Safe on !RT
as well.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index cfc6d4448aa5..63fd6d78be27 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -341,8 +341,14 @@ int mnt_want_write(struct vfsmount *mnt) * incremented count after it has set MNT_WRITE_HOLD. */ smp_mb(); - while (mnt->mnt_flags & MNT_WRITE_HOLD) + /* + * No need to keep preemption disabled accross the spin loop. + */ + while (mnt->mnt_flags & MNT_WRITE_HOLD) { + preempt_enable(); cpu_relax(); + preempt_disable(); + } /* * After the slowpath clears MNT_WRITE_HOLD, mnt_is_readonly will * be set to match its requirements. So we must not load that until @@ -352,9 +358,7 @@ int mnt_want_write(struct vfsmount *mnt) if (__mnt_is_readonly(mnt)) { mnt_dec_writers(mnt); ret = -EROFS; - goto out; } -out: preempt_enable(); return ret; } |